1. Field of the Invention
The present invention relates to the visualization of a heart by using the TSI (Tissue Strain Imaging) method and, more particularly, to the mapping of the shortening information of the heart in the long axis direction in a contraction phase to a short axis image or the mapping of the thickening information of the heart in the cardiac wall thickness direction to a short axis image.
2. Description of the Related Art
In general, with regards to a living tissue such as cardiac muscle, it is very important for the diagnosis of the tissue to objectively and quantitatively evaluate the motion or function of the tissue. In image diagnosis using an ultrasonic image processing apparatus, various quantitative evaluation methods have been tried mainly for heart cases. For example, it is known that the normal cardiac muscle thickens in the wall thickness direction (short axis), and shortens in the long axis direction in a contraction phase. It is generally said that the motion directions of thickening and shortening are perpendicular to each other and exhibit different mechanisms. It is suggested that evaluating the myocardial wall motion by observing these motions makes it possible to support diagnosis associated with a heart disease such as myocardial infarction.
In a conventional ultrasonic diagnostic apparatus, however, the following problems arise. While a short axis view is obtained and observed, no biometric information perpendicular to a scanning plane of the short axis view can be acquired due to the characteristics of the ultrasonic diagnostic apparatus. Therefore, shortening information cannot be simultaneously expressed. In addition, while a apical long axis approach is obtained and observed by, for example, the tissue Doppler method, thickening information cannot be simultaneously expressed because of a Doppler angle limitation.